Question

Complete equation of the line through (1,4) and (2,2)

Answer 1

y = -2x + 6

Explanation:

y=mx + c

m is the gradient and c is the y intercept

m = (y 2 - y 1) / (x 2 - x 1) = (2-4) / ( 2-1) = -2

y= -2x + c

To find c, just sub one of the coordinates into the eqn:

By using the coordinates (1,4)

4 = -2(1) + c

c = 6

Therefore, the equation is y = -2x + 6